Side columns of a sidewall structure of a railway coal hopper car with the existing structure are arranged at the outer side of the car body, as one of the main load bearing components of the sidewall, in view of the requirements of high strength and low self weight, the side columns are of hollow rectangular tubular structures with large cross sections, and since the side columns are arranged at the outer side of the car body, spaces between the side columns are not used. In addition, the connection of the side columns and a sidewall panel is formed by riveting with rivets, because of the numerous rivets, the strength of the sidewall panel is reduced by the rivet holes on one hand, and on the other hand, coal accumulation conditions are liable to occur at the numerous rivet heads and the weight and cost of the rivets are increased as well.